I picked one of these up after the recent price drop, and must say I really like it. I haven't had enough time investment yet to get into deep sound design, but it won me over pretty quickly. It's not going to replace my P10 but I didn't buy it for that purpose... the combination of the sound, the compact size, the UI/workflow, the Poly AT, etc. is something I didn't have all in one and I'm not sure is even really available any other way. I never did pull the plug on the Take5 or Teo5, not because I didn't like them but because I felt those bases were already covered better with the synths I already had -- I'm also a bit of a snob for a fully analog signal path, which the Fourm satisfies.
I've been listening to it mostly dry, looking forward to combining it with some FX and spending more time with it but overall I'd say at the current price point of $799 USD I'd say its a gem really.